This invention relates in general to the amplification of transmitted signals for use with a bidirectional transceiver/antenna system. More particularly, the invention relates to apparatus, methods, and systems implemented in the antenna path of a transceiver for amplification of transmitted signals without detriment to received signals.
A radio transceiver is well known in the art as a combination transmitter-receiver that uses many of the same components for both transmission and reception of radio signals. Bidirectional radio antennas are equally well known in the art for providing a single bidirectional signal path in two opposing directions for radio transmission and reception.
Although many applications for radio transceiver and antenna systems exist in the art, small, low-cost and short-range radio modules, such as the Ericsson Bluetooth module, available from Ericsson Telefonaktiebolaget L.M. of Sweden, are increasingly used for many different types of applications requiring a communication interface. Typical devices in which the Bluetooth transceiver module can be used are portable computers, hand-held wireless devices, digital cameras, computer peripherals, and mobile phone accessories. Typically, small relatively low-cost, short-range radio transceivers are mass-produced in a standardized self-contained package or module.
A serious problem with radio transceivers in general, and small, low cost radio transceivers such as Bluetooth modules in particular, is encountered when increased output signal power is desired. Generally speaking, output signal amplification can be achieved most simply by providing an amplifier in the transmission circuitry of the transceiver without adversely affecting the reception circuitry. Although this amplification solution is acceptable in custom transceiver designs, the cost and time advantages inherent in mass-production and standardization are lost if off-the-shelf transceivers are to be used. It is not possible to simply add an amplifier to the transmission circuitry of a Bluetooth radio module, for example. There is, therefore, a need for a cost-effective solution to the problem of increasing output signal power while simultaneously avoiding detriment to signal reception without modifying off-the-shelf radio transceiver modules and/or bidirectional antennas.
Disclosed is amplification apparatus for use with a transceiver having a bidirectional signal path between the transceiver input/output port and a bidirectional input/output antenna. The apparatus has a first divider coupled to the bidirectional signal path at the input/output port of the transceiver. The first divider divides the bidirectional signal path into an independent transmission path and an independent reception path. A transmission signal amplifier is included in the transmission path for amplifying the transmitted signal. A second divider recombines the independent transmission path and reception path into a bidirectional signal path for coupling with a bidirectional antenna.
Also disclosed is a method of signal amplification performed between a transceiver input/output port and a bidirectional antenna. The method amplifies a transceiver output signal to produce an amplified output signal. The amplified output signal is then broadcast using the bidirectional antenna. Input signals received using the bidirectional antenna are allowed to pass into the input of the transceiver without sacrificing receiver performance by bypassing the signal path used to achieve output signal amplification.
Additionally, a transceiver system is disclosed providing transceiver apparatus having a bidirectional signal path including a transmit/receive port, amplification apparatus for amplifying transmitted signals, a receive path, and a transmit/receive antenna.
The invention apparatus, method, and system embodiments disclosed include implementation of the inventions using a Bluetooth radio module. Bluetooth is a registered trademark of Telefonaktiebolaget L. M. Ericsson of Sweden. Use of the invention with Bluetooth radio modules provides technical advantages in cost and flexibility for adapting the modules to various applications.
An additional technical advantage of the invention is that amplification of transmitted signals can be provided without detriment to received signals using existing radio transceivers and antennas without alteration of the transceiver and antenna hardware.
Further technical advantages are realized by the invention in that the transmitted signal of a transceiver can be increased by orders of magnitude over the actual transceiver output amplitude providing an increased transmission range for a given transceiver.